Contrivance for treating materials within a gas atmosphere of increased pressure



May 7, 1940. w. DODERER CONTRIVANCE FOR TREATING MATERIALS WITHIN A GAS ATMOSPHERE 0F INCREASED PRESSURE Filed Aug. 12, 1938 2 Sheets-Sheet l W. DODERER 0R T May 7, 1940.

REATING- MATERIALS A GAS ATMOSPHERE Filed Aug. 12, 1938' 2 Sheets-Sheet 2 111,111, 'IIII'IIIIIIIIIIIIIIIIA I Patented May 7, 1940 UNITED STATES CONTRIVANCE FOR TREATING MATERIALS WITHIN A GAS ATMOSPHERE F IN CREASED PRESSURE Wilhelm Doderer, Essen. Germany Application August 12, 1938, Serial No. 224,445 A In Germany August 21, 1937' 10 Claims. (01. 263-6) The invention relates to contrivances operated at increased inner pressure for the treatment of any desired materials, such as for instance furnaces for annealing iron-sheets in an atmosphere of a suitable protecting gas being held at a certain overpressure and more particularly to such contrivances of the kind mentioned before which are operated continuously so that the material to be treated entersand leaves the contrivance 16 in a continuous manner.

It is known to improve the quality of iron sheets or other materials by annealing the material in an atmosphere consisting of a suitable inert or reducing gaseous medium, such medium being called in the specification hereinafter protecting gas. For such treatment, contrivances are used which comprise means for annealing and cooling the material in such a way that the temperature of the material is raised and thereafter decreased in the desired manner. The inner rooms of such contrivances are filled with the protecting gas, the latter being held at a certain overpressure against the atmosphere outside the contrivance, so that air is prevented from entering the treating room.

Annealing plants through which goods are continuously carried are often provided at the entrance and at the exit with locks. These locks consist of a chamber which is closed at opposite sides by doors, one of those doors being arranged on the side towards the annealing room and the other door on the side towards the open air. The goods to be annealed will be introduced from outside into the lock-chamber, then the 35 outer door will be closed and the goods after opening the inner door carried into the annealing chamber. Seals in the form of such locks are disadvantageous in that each time the outer door of the lock is opened air enters the lock-chamber and later-on tends to enter the annealing room, filled with the protecting gas, when theinner door of the lock-chamber is opened. In order to prevent the air from flowing from the lock-chamber into the annealing chamber, the lock-chamber has to be freed from air by blowing protecting gas through it before the inner door is opened. Such procedure, however, involves considerable losses of valuable protecting gas.

It is advantageous to provide the entrance and exit of continuous annealing furnaces and the like with an automatic multiple seal consisting of a series of movable flaps which are opened by the 5:, goods themselves passing throughthe series of flaps and which close after the passage of the goods.

The main object of my present invention is to provide improvements in the above mentioned annealing furnaces or the like which will render efiective the said multiple seal, even in cases where a so-called walking beam conveyor is made use of for transporting the material to be treated through the annealing chamber or furnace.

The multiple seal with movable flaps is based on the principle of providing a row of-chambers at the entrance and exit of a plant which is filled with protecting gas under pressure. The chambers are separated from each other by movable fiaps which are fairly gas-tight. If there is an overpressure (pressure above the atmosphere) in the annealing chamber or the rest of the plant, then a free flow of .gas through the series-of flapscorresponding to the total 'difference of pressure between the annealing chamber and the open atmosphere cannot occur, but only a very small quantity of gas may flow through the seals in accordance with the very small differ ence of pressure between the adjacent chambers.

The loss of valuable protecting gas when using a multiple seal of the kind referred to above, is reduced to a considerable extent owing to the fact that the difference in pressure between the individual chambers of the multiple seal is very low. so that such a multiple seal may be advantageously used even in cases where the treating chamber of such plant is operated'at rather a high pressure.

The multiple seal further prevents the atmospheric air from-entering the treating chamber by diffusion if the difference of pressure between the treating chamber of the plant and the free air is very low. I In other words, if the treating cham-'- ber is operated at a comparatively low pressure there is the danger of diffusion between air and protecting gas. Such diffusion will be eliminated in the multiple seal according to the invention in one direction through space I.

sisting of several flaps which are moved and automatically shut by the material to be treated, I arrange the stationary beams of a walking beam conveyor within a range of the space in such a way that they lie at right angles to the direction of said conveyor and I also arrange said flaps in such a manner that they close the space between the upper edge of the stationary cross-beams and the cover of the casing which is provided at the entrance and exit of the furnace. If there is no material within the range of the flap sealing, the lower end of each said flap lies on the upper edge of the corresponding stationary cross-beam.

According to the arrangement of the stationary beams of the walking beam conveyor, I provide in the same way that the movable beams of said conveyor shall lie at right angles to the direction of movement of the walking beam conveyor.

Furthermore, my invention relates to the construction of the supporting frame for the movable beams of the walking beam conveyor within the range of the flap sealing in an essentially box-like shape, the space between the box-like supporting frame and the fixed cross beams, on the one hand, and the space between the said supporting frame and the bottom of the casing, on the other hand, being sealed by movable means which are adapted to follow the vertical movements of the walking beam conveyor and of the supporting frame respectively.

My invention provides for a complete sealing of the casing through which the walking beam conveyor extends into the open air. This seal is effected, on the onehand, by the flaps which are opened and shut automatically by the material to be treated and, on the other hand, by movable means which fit against the box-like supporting frame of the walking beam conveyor and follow its vertical movements and do not hinder the horizontal movement of the walking beam conveyor.

My invention further relates to other objects and features which will be seen in the following detailed description of my invention and the special properties of the invention will also be described and explained in detail with reference to the accompanying drawings, in which:

Fig. 1 is a vertical, longitudinal section through a seal according to my invention and a part of the adjacent furnace,

Fig. 2 shows a part of a horizontal section on line 11-11 of Fig. 1,

Fig. 3 is a vertical cross section on line IIIIII of Fig. 1, omitting the details which are not necessary for the explanation. V

Fig. 4 shows in an enlarged scale a section through the means or parts effecting the seal between the stationary cross-beams and the supporting frame of the walking beam conveyor.

Fig. 5 shows in an enlarged scale the seal between the casing and the flap shaft.

Fig. 6 shows in an enlarged scale some of the details of the flap mounting as shown in Fig. 1.

In the drawings, the space where the heat treatment of the material is going on is marked I. Space I has the form of a channel in which are provided suitable heating and cooling devices. The goods to be heated are carried continuously Space I is built of suitable refractory material 2. For the transport of the goods through the space I I provide a so-called walking beam conveyor which is formed by a series of beams 3 and 4 lying in the longitudinal direction of the chamber and which alternate with one another. Beams 4 are stationary and arranged in one plane. Beams 3 lying between beams 4 are carried by supports 5 which are fastened to a main girder 6. This main girder 6 is arranged underneath the refractory brickwork I which forms the bottom of the heat treatment chamber.

The main movable girder 6 of the walking beam conveyor is continually or periodically moved in such a way that it is carried backward under the level of the stationary beams for a certain distance in the direction opposite to the transport of the goods, then lifted above the level of the stationary beams, then moved forward horizontally for the same distance as it was moved backward formerly, and then lowered into the initial position.

Also the movable beams 3 of the walking beam conveyor perform suitable movements together with the main girder Ii. The complete arrangement is made in, such a way that in the lower position of the walking beam conveyor the movable beams 3 may pass freely underneath the annealing goods lying upon the stationary beams 4. On moving upwards, the main girder 6 and the movable beams 3 lift the annealing goods from the stationary beams 4 and forward them during the subsequent horizontal movement of the main girder. If the maingirder 6 is then lowered the goods are delivered back again onto the stationary beams t but at a point which is advanced from the previous position of the annealing goods by the distance of the horizontal movement of the walking beam conveyor.

Thus the annealing goods are passed through the space of the furnace.

Various contrivances may be used for effecting the movement of the walking beam conveyor. Fig. 1 shows, for example, that the walking beam conveyor rests on rollers 8 which are fitted to the angular levers 9. These angular levers 9 are actuated by a common tie-rod. If for instance the tie-rod is moved in the direction of the arrow II, the levers 9 rotate in anticlockwise direction and the main girder 6 of the walking beam conveyor is lowered.

The horizontal movement of the walking beam conveyor is suitably effected by a crank-drive and connecting rod in a well known manner.

At the entrance and/or exitof the treating channel I there is arranged a casing II consisting of machined cast iron plates or thelike. The casing Ii, near the entrance to the treating chamber, is fitted with an extension I3 into which the end of the main girder 6 of the walking beam conveyor projects. An extension I5of the main girder which traverses longidinally through the casing II is connected to the end of the main girder 6 by means of supports I 4. The longitudinal girders I5 serve to support the movable beams of the walking beam conveyor within the range of the casing II.

As may be seen from Fig. 3, the longitudinal girders I5 of the walking beam conveyor within the range of the casing II are equipped with a box-like jacket I6 which extends up: to near the side walls of the casing II, thus effecting a. fairly gas-tight seal with the side walls of the casing I I.

Within the range of the longitudinal girders I5, the carrying beams of the walking beam conveyor extend transversely to the transport direction. The carrying beams are formed by the stationary beams I1 and the movable beams IS. The beams I8 are carried by continuous walls I9 which are gas-tightly connected with the box-like jacket I6 of the main girders I5. The stationary cross-beams II are supported at both sides on brackets 20 at the side walls of the casing II.

The stationary beams II are spaced from one another sufiiciently far so that the movable carrying beams I8, each of which is located between two stationary beams II, are able to perform the required horizontal and vertical movements.

Should it happen that the material to be treated is of small size so that it would fall downward. between two stationary beams II, the stationary beams I! may be connected with each other by two or more webs 2| (see Figs. 3 and 4). The movable beams I8 within the range of the webs 2| are provided with suitable recesses 22. The annealing goods are, therefore, carried by the stationary cross-beams I1 and the connecting webs 2| when the movable beams I8 are below the level of the stationary beams. Within the casing II near its cover there is a plurality of horizontal shafts 23, one end of each being arranged rotatably in a bearing 24 and the other end penetrates the wall of the casing II and which is sealed by means of a stufiing box 25. In the interior of the casing II there is a flap 26 attached to every shaft 23. The lower end of the flap 26 (see Fig. 4) lies within the range of the flange on the upper side of the stationary cross beam I'I. As marked at 2! in Fig. 4 the lower edge of each flap 26 is laterally bent and provided with a felt cover 28 or the like which rests against the upper side of the stationary cross beams I! if the flap is shut. The flaps 26 extend transversely to the transport direction of the goods as shown in Fig. 1. If the goods to be treated, for instance a sheet iron plate a (Fig. l), is transported by the movement of the walking beam conveyor in the direction of arrow b, the material with its front edge pushes against the flaps 26 thus lifting them by so much that the goods are moved through the space between the flaps and the stationary beams of the walking beam conveyor. The felt cover 28 thus prevents the upper side of the material to be treated from being scratched by the lower edge of the flaps 26 and on the other hand the felt cover 28 serves to provide a seal between the flap and the respective stationary carrying beam I'I. As soon as the end of the material to be treated has again left the range of the flaps 26, this flap closes automatically against the action of a counter weight 29 which is arranged upon the outer projecting end of the flap shaft 23, as shown in Fig. 3.

Fig. 5 of the drawings shows the sealing of the shaft 23 to the casing II. In the cover of the casing II above each shaft 2! there is provided a slot 3I in which is arranged a felt strip 32 or the like which is kept tight against the flap shaft 23 by means of a spring 33. The space between the shaft 23 and the casing shaft II can thus be effectively sealed. If the felt packing wears out it may easily be replaced by taking off the cover 34 of the slot 3|.

In order to seal the space between the stationary beam I1 and the box-like jacket I6 of the main girder I5, plates 35 consisting of corrugated flexible sheet iron may be provided for as shown in Fig. 4. The corrugated sheet plates 35 are fastened to the beams I! in a gas-tight manner. The lower end of each plate 35 is bent horizontally and fits against the upper side of the girder jacket I6. Springs 36 force the horizontal portions 31 of the plates 35 against the box-like jacket I6 in such a way that the horizontal movement of the box I6 and thus of the main girders I5 is rendered possible without bringing the plates 35 substantially out of their vertical position. The sealing at this place is improved in that the upper side of the box-like jacket is lubricated by a special means.

A plurality of sealing flaps 38 as shown 1 act against the lower side of the box-like jacket I6. The flaps 38 are rotatably supported upon the bottom of the casing II. Preferably they consist of a rectangular bent robust sheet plate. The longitudinal edge 39 resulting from the rec-, tangular bending of the plate is situated in a small groove 41 (as shown in Fig. 6) of the casing I I which is likewise provided with a suitable bearing metal 48 if necessary and a suitable lubricant 49. Fig. 1 shows that the one end of the flaps 38 fits against the lower side of the girder jacket I6. Tension springs 48 which may be influenced from; outside by the adjusting screws 4I act upon the other end of the flaps 38. The springs 40 always keep the flaps 38 against the lower side of the box I6. The tension of the springs 46 is adjusted in' such a manner that the flaps 38 are able to follow the vertical movements of the walking beam conveyor and of the box-like jacket I6 respectively without stopping the horizontal movement of the jacket I6.

The gas-tight sealing within the casing II is, therefore, effected by the flaps 26 which close the space for the goods to be treated, by the resilient walls 35 and by the flaps 38 which seal the space in which jacket I6 of the main girder I5 moves. Fig. 3 shows the co-action-of the sealing flaps 26 and 38 and of the resilient walls 35. All movable elements, the flaps 26 and 38 as Well as the walls 35 and the jacket I6 of the main girders I5, reach up to near the side walls of the easing II. In order to protect the flaps 26 facing the furnace against the radiations from the annealing space I it is preferable to provide at the entrance of the annealing space I, and also at the exit end, balanced flaps 42 consisting of heat resisting material. These flaps 42 need not be arranged gas-tightly against'the, casing II but only serve to prevent the heat radiation. I

In order to obtain a gas tight sealing of the movable elements in the casing II the side walls of the casing are suitably greased by a lubri eating means. The lower part of the casing II' in this case serves as a storage tank for the sealing oil so that the edges 39 of the flaps 38 are constantly covered by an oil film. The lubricatbricating oil may be suitably distributed along the side walls of the casing II and then flows grad-' ually downwards thus effecting on theone hand a seal between the resilient walls 35 and the casing II and on the other hand it seals the gap between the jacket I 6 and the casing II. v

Since the sealing of the space above and below the box-like jacket is fairly good it is preferable to connect the individual compartments between the flaps underneath the jacket I6 with thecompartments above the jacket I6, for instance by a series of pipes 46; When thewalking beam conveyor moves downwards, the volume of the space between the jacket I Band the bottom of the easing II becomes smaller and the space in the casing above the jacket I6 becomes larger. A cor responding volume of the gas from the space underneath the jacket I6 may flow through the pipes 46 into the space above the jacket I6. The pressuremay, in the same way, be equalised when the box-like jacket [6 rises.

I have now described the present invention on the lines of a preferred embodiment thereof, but my invention is not limited to the embodiment as described and shown. The invention may obviously be varied within the scope of the following claims.

I claim:

1. Closure means for contrivances for the treatment of materials in a gaseous atmosphere of increased pressure against the open air, such as furnaces for annealing of metal sheets, such contrivances being provided with a walking beam conveyor for moving the material to be treated through the treating chamber, said walking beam conveyor having alternately arranged movable beams and stationary beams, comprising a movable flap shutting-01f the chamber-opening passed by the material to be treated, said movable flap being arranged so as to swing round a horizontal axis and to be opened by the material moved upon the walking beam conveyor, said flap being self-closing after the material to be treated has come out of contact with said flap, a stationary beam of the walking beam conveyor placed within the moving range of said flap so that the lower edge of said flap fits against said stationary beam when in closing position, said stationary beam connected in a gas-tight manner to the inner walls of the treating chamher, the movable and the stationary beams of said conveyor extending cross-wise to the moving direction of said conveyor within the range of said flap.

2. Closure means for contrivances for the treatment of materials in a gaseous atmosphere of increased pressure against the open air, such as furnaces for annealing of metal sheets, such contrivances being provided with a walking beam conveyor for moving the material to be treated through the treating chamber, said walking beam conveyor having alternately arranged movable beams and stationary beams, comprising a series of movable flaps, each of said flaps shutting oif the chamber opening passed by the material to be treated, said movable flaps being arranged so as to swing round a horizontal axis and to be opened by-the material moved upon the walking beam conveyor, said flaps being self-closing after the material to be treated has come out of contact with each of said flaps, a stationary beam of the walking beam conveyor arranged within the moving range of each of said flaps so that it the lower edge of each flap fits against one of said stationary beams when in closing position,

said stationary beams connected in a gas-tight manner to the inner walls of the treating chamher, the movable and the stationary beams of said conveyor extending crosswise to the moving direction of said conveyor within the range of said flap.

3. Closure means for contrivances for the treatment of materials in a gaseous atmosphere of increased pressure against the open air, such as furnaces for annealing of metal sheets, such contrivances being provided with a walking beam conveyor for moving the material to be treated through the treating chamber, said walking beam conveyor having alternately arranged movable beams and stationary beams, comprising a movable fiap shutting off the chamber opening passed by the material tov be treated, said movable flap being arranged so as to swing round a horizontal axis and to be opened by the material moved upon the walking beam conveyor, said flap being self-closing after the material to be treated has come out of contact with said flap, a stationary beam of the walking beam conveyor placed within the moving range of said flap so that the lower edge of said flap fits against said stationary beam when in closing position, said stationary beam connected in a gas-tight manner to the inner walls of the treating chamber, the movable and the stationary beams of said conveyor extending crosswise to the moving direction of said conveyor within the range of said flap, and means for closing the space between the axis of said flap and the roof of the treating chamber opening, said means being independent from said flap and being accessible from outside.

4. Closure means for contrivances for the treatment of materials in a gaseous atmosphere of increased pressure against the open air, such as furnaces for annealing of metal sheets, such contrivances being provided with a walking beam conveyor for moving the material to be treated through the treating chamber, said walking beam conveyor having alternately arranged movable beams and stationary beams, comprising a movable flap shutting oi? the chamber opening passed by the material to be treated, said movable flap being arranged so as to swing round a horizontal axis and to be opened by the material moved upon the walking beam conveyor, said flap being self-closing after the material to be treated has come out of contact with said flap, a stationary beam of the walking beam conveyor placed within the moving range of said flap so that the lower edge of said flap fits against said stationary beam when in closing position, said stationary beam connected in a gas-tight manner to the inner walls of the treating chamber, the movable and the stationary beams of said conveyor extending cross-wise to the moving direction of said conveyor within the range of said flap, the movable beams of said walking beam conveyor being connected resiliently in a gastight manner with the rigid beams thereof within the range of said flaps,

5. Closure means for contrivances for the treatment of materials in a gaseous atmosphere of increased pressure against the open air, such as furnaces for annealing of metal sheets, such contrivances being provided with a walking beam conveyor for moving the material to be treated through the treating chamber, said walking beam conveyor having alternately arranged movable beams and stationary beams, comprising a movable fiap shutting off the chamber opening passed by the material to be treated, said movable flap being arranged so as to swing round a horizontal axis and to be opened by the material moved upon the walking beam conveyor, said flap being self-closing after thematerial to be treated has come out of contact with said iiap, a stationary beam of the walking beam conveyor placed within the moving range of said flap so that the lower edge of said flap fits against said stationary beam when in closing position, said stationary beam connected in a gas-tight manner to the inner Walls of the treating chamber, the movable and the stationary beams of saidconveyor extending crosswise to the moving direction of said conveyor within the range of said flap, said movable beams arranged within the range of said fiap being fixed to a carrier extending in the moving direction of said conveyor being closed on its upper and lower side and fitsupported upon the bottom of said chamber opening.

'7. Closure means as per claim 5 comprising flexible plates attached to the stationary beams of said walking beam conveyor in a gas-tight manner and fitting against the upper side'of said closed carrier of the movable walking beam.

8. Closure means asper claim 5 comprising flexible plates attached to the stationary beams of said walking beam conveyor iii a gas-tight manner and held against said upper side of the carrier by adjustable springs so that the plates may fit against the carrier during its reciproeating movement.

9. Closure means as per claim 2, the spaces between the movable flaps which fit against the stationary beams of said walking beam' conveyor being connected with the space between the lower side of the movable beams and the bottom-of the chamber opening in such a manner that the gas pressure in said spaces may be equalized.

10; Apparatus as defined in claim 1, said walking beam conveyor having portions extending within and without said treating chamber, the movable beams of said respective portions being carried by longitudinally movable carriers, the

carrier for said beams within said treating chamher being arranged at a lower-level than the carrierjfor said other beams and being operae tively connected with said other carrier.

' WILI-IELM DODERER. 

